That was probably the fatal 1975 decision, or at least the one that led to SVN's 55-day disintegration. I've heard that supplies were too low to enable a proper defense- artillery rounds were limited to 10 per day or something along those lines. Let's say Thieu doesn't take leave of his senses and orders the CH held at all costs, and the best remaining units try to establish a viable defense line. How long can they hold out?